Gun unit for gun perforators



Patented Sept. 7, 1937 UNITED STATES PATENT OFFICE GUN UNIT FOR GUN PERFORA'IORS Application June 17, 1935, Serial No. 27,024

10 Claims.

My invention relates to gun units for gun perforators designed for perforating well casing in situ by gun fire, and is a continuation in part of Patent No. 2,043340 issued June 9, 1936.

First, to provide a particularly compact gun unit which is so shaped that it may be mounted in a laterally extending position within a cylindrical gun body and of such size as to fit within comparatively small well casing.

10 Second, to provide a gun unit which although compact is designed to withstand a comparatively heavy charge of explosive even when flred when the gun unit is submerged to great depths in liquid.

15 'I'hird, to provide a gun unit which incorporates a. novelly arranged sealing means between the explosive chamber and the gun barrel which not only functions to delay or retard expansion of the explosive in order to obtain higher projectile velocity in a short barrel, but also localizes or minimizes the pressure area of the barrel; that is, the area. subjected to the pressure exerted by the explosive, thereby minimizing the stresses tending to blow the barrel from the chamber 25 block or otherwise damage the gun unit.

Fourth, to provide a novel means of retaining the bullet in position at the breach end of the barrel.

Fifth, to provide a gun unit having a minimum 30 number of parts which are capable of quick assembly a.nd disassembly, and which incorporate easily positioned sealing adapted to seal the gun unit againstextreme external hydrostatic pressures.

35 With these and other objects in view as may appear hereinafter, reference is made to the accompanying drawng, in which:

Fig. 1 is an elevational view of a gun perforator incorporating my gun units.

40 Fig. 2 is an enlarged sectional view through 22 of Fig. 1 showing the gun body in transverse section and the gun unit in longitudinal section With the bullet, cartridge, and contact means shown in elevation.

Fig. 3 is a transverse sectional view of the gun unit taken substantially through 3-3 of Fig. 2 With the cartridge removed.

The gun perforator With which my gun unit is adapted to be used comprises a gun body I in the form of an elongated cylinder With a plurality of laterally directed sockets Ia. Each socket is divided into an inner part Ib and an outer part |c by an internal fiange I d. The outer part ic is provided With screwthreads. At the base of each socket there is mounted a contact plate 2 insulated from the gun body. The contact plat-es of the several sockets are individually connected With a controller or selector mechahism. not shown, which is carried in the upper end of the gun body. The gun perforator is at- 5 tached to a cab1e 3 which both supports the gun perforator and supplies electrical energy thereto.

A plurality of my gun units are incorporated in each gun perforator and their charges are adapted to be fired electrically in sequential order by said controller. A chamber block H constitutes the dominating member of each gun unit. Said clgamber block is generally cylindrical in form and adapted to fit within the internal flange ld of a socket Ia. The outer portion of the chamber block is provided With a screw threaded enlargement Ila adapted to engage the screwthreaded outer part l c of the corresponding socket. The inner shoulder of the enlargement Ila and outer shoulder formed by the flange I (1 confront and a sealing washer |2 is positioned therebetween to seal the inner part Ib of the socket.

At its outer or muzzle end the chamber block is provided With an internally threaded barrel socket Ilb which is adapted to receive a correspondingly threaded barrel [3. The muzzle end of the barrel protrudes beyond the chamber block. Similarly, the muzzle end of the chamber block protrudes beyond its screwthreaded enlargement i Ia. The protruding portions of the barrel [3 and chamber block are suitably shaped to receive wrenches for securing the barrel in the chamber block and the chamber block in the gun body; however, these protruding portions do not project beyond the circle defined by the gun body.

Inwardly from the barrel |3, the chamber block defines an explosive receiving chamber Hc rel. A small opening is provided between the inner end of the chamber Ilc and the inner end of the chamber block. This opening receives a small insulated contact pin I4, and the opening is enlarged at the chamber Ilc to receive a contact head I4a fonning a part of the contact pin. The end of the contact pin l4 protruding from the gun unit into the socket l a is provided With a suitable contact means I4b engageable With the r contact plate 2.

The chamber llc is adapted to receive a cartridge l5, preferably formed of insulating material and containing an explosive through which extends a fusible wire I5a. Terminals at the ends connect one end of the wire With the contact head IJia and ground the other or orward end thereof.

Between the chamber llc and the breach end of the barrel |3 is positioned an expansion retarding and pressure localizing disk Is. The disk I6 is flat except for a peripheral cylindrical skirt or wall fl6a which projects toward the chamber Me and fits in a slight enlargement provided at the forward end thereof. The functions of this disk will be brought out in more detail hereinafter.

The barrel l3 is provided with a bore i3a therethrough in axial alinement with the chamber and somewhat smaller in diameter. A bullet I is fitted in the bore and occupies a large part of its length.

The outer or muzzle end of the barrel is provided with 'a shallow recess orming a shoulder around the outer end of the bore and which receives a cup-shaped sealing disk H8 having an outwardly facing peripheral wal] l8a. The disk is backed by a sealing washer i9. The disk l8 is pressed into place and its wall I8a and the washer II9 are forced by external hydrostatic pressure to seal the bore of the barrel.

The barrel l3 is necessarily very short and it is highly desirable that the bullet always be as near the breach end of tli barrel as possible. This is insured by a small spring 20 inserted between the sealing disk H8 and the pointed end of the bullet.

The screwthreaded connection between the barrel 93 and chamber block is sealed at the inner end of their threads by an annular sealing ring 2! preferably formed of rubber and having a chan.nel in its forward side defining skirt portions which are forced by external pressure tightly against the adjacent surfaces.

Referer.e 1s again directed to the expansion retarding and pressure localizing disk I5. As the name implies, the disk l with its wall or skirt l6a performs two important functions; namely, retarding the expansion of the explosive to build up pressure before acting upon the bullet, and localizing the area of the barrel subjected to the force of the explosion.

It is manifestly impossible in a gun unit of this character to provide anything but the shortest of barrels, while it is necessary that a comparativ ely heavy bullet have sufiicient velocity in its extremely short travel to penetrate not only one, but two or three strings of casing. The disk l6, while formed of comparatively soft material. suflieiently delays the expansion of the explosive to increase greatly the pressure of the explosive with the result that muzzle velocities comparable with rifie bullets are obtained.

The generation of such high pressures naturally cause some expansion between the barrel and chamber block so that without the skirt or wall at the periphery of the disk |6, the pressure generated would be applied over the entire breach end surface of the barrel. The force of such high pressure over this large an area places extreme stresses on the threaded connection between the barrel and the chamber block as well as that portion of the chamber block between its enlargement I Ia and breach end of the barrel. In other words, assuming that the area indicated by A of the chamber He is one square inch, and that the area indicated by B of the barrel is two square inches, and that the pressure generated within the chamber is 150,000 pounds per square inch, it follows that the force en the barrel with the disk l5 and its skirt I6a is only 150,000

pounds; whereas, without the skirt l6a, the force tending to blow out the barrel or break the chamber block at the breach end of the barrel would be 300,000 pounds.

Though I have shown and described a particular embodiment of my invention, I do not Wish to be limited thereto but desire to include in the scope of my invention such embodiments as are embraced in the appended claims.

I claim:

1. A gun unit for gun type well casing perforators comprising; a chamber block having an explosive receiving chamber and a barrel receiving portion of larger diameter than the chamber; a barrel removably securable in said chamber block; and a skirted disk of smaller diameter than said barrel receiving portion interposed between said barrel and chamber with its skirt directed toward the chamber.

2. A gun unit for gun type well casing perforators comprising; a chamber block; a barrel adapted to be screwthreadedly secured thereto and defining therewith an explosive receiving chamber of larger diameter and a projectile receiving bore of smaller diameter; a sealing ring interposed between the barrel and chamber block at the inner or breach end of the barrel; a sealing disk closing the bore of said barrel; said ring and disk sealing the chamber against external liquids; a projectile in said bore; and a yieldable means interposed between said disk and projectile for holding said projectile at the breach end of the barrel.

3. A gun unit for gun type well casing perforators comprising; a chamber block; a removable barrel adapted to fit said chamber block and define therewith an explosive receiving chamber, said barrel being larger in diametrical than said chamber; a sealing means interposed between the barrel and chamber responsive to pressures from within the chamber for minimizing the area of said barrel subjected thereto; and a. sealing means between the barrel and. chamber block, and another sealing means at the muzzle of said barrel adapted to seal the chamber from liquids externally of the gun unit.

4. A gun unit for gun type well casing perforators comprising; a chamber block; a removable barrel adapted to fit said chamber block and deflne therewlth an explosive receiving chamber, said barrel being larger in diametrical section than said chamber; a sealing means between the barrel and chamber block, and another sealing means at the muzzle of said barrel adapted to seal the chamber from liquids externally of the gun unit; said barrel having a projectile receiving bore; and yieldable means interposed between the muzzle sealing means and a projectile within the bore for retaining the projectile at the breach end of the barrel adjacent the explosive receiving chamber.

5. The combination with a gun unit for well casing perforators wherein an explosive charge is retained in a chamber block by a plug of larger diameter than the charge; of a disk interposed between the plug and chamber and having a peripheral skirt directed into the chamber, the disk being responsive to pressures generated within the chamber to maintain the area of the plug subjected to such pressure substantially equal to the section of the chamber.

6. A gun unit for a gun perforator: a, chamber block having an explosive receiving chamber and a barrel receiving recess extending therefrom, said recess being substantially larger in diameter than said chamber and forming therewith a shouider; a gun barrel adapted to be removably mounted in said recess for access to said chamber and abuis said shoulder; and a sealing means interposed between said chamber and gun barrel to restrain radial flow of gases between said shoulder and gun barrel upon ignition of an exa confrontingface exposed thereto; and a sealing membe covering said fase and having a skirted perphery directed into said chamber for minimizing radial flow of gases between the gun barrel and chamber block shoulder during ignition of an expiosive charge in said chamber.

8. A gun unit for a gun perforator: a chamber block having an explosive receiving chamber and a barrel receiving recess extendng therefrom,

said recess being substantially larger in diameter than said chamber and formng therewith a shoulder; a. gun barrel adapted to be removabiy mounted in said recess for access to said chamber and abut said shoulder; a. sealing means interposed between said chamber and gun barrel to restrain radial flow of gases between said shoulder and gun barrel upon ignition of an expiosive in said chamber; a first deieterious fluid seal between said barrel and its recess; and a second deleterious fluid seal at the outer end of said gun barrel.

9. A gun unit for a gun perforator: a chamber block having an explosive receiving chamber and a barrel receiving recess extending therefrom, said recess being substantially langer in diameter than said chamber and forming therewith a shoulder; a. gun barrel adapted to be removably mounted in said recess for access to said chamber and abut said shoulder, said gun barrel hav ing a bore smaller than said chamber to define a. confronting face exposed thereto; a sealing member covering sad face and having a skirted periphery drected into said chamber for minimizng radial flow of gases between the gun barrel and chamber block shoulder during ignition of an explosive charge in said chamber; a

first deleterous fluid seal betweensaid barrel and its recess; and a second deleterious fluid seal at the outer end of said gun barrel.

10. A gun unit for a gun perforator: a chamber block having an explosive receiving chamber and a. barrel receiving recess extending therefrom, said recess being substantially larger in diameter than said chamber and forming therewith a shouider; a gun barrel adapted to be removably mounted in said recess f0r access to said chamber and abut said shoulder; a. first skirted disk at the inner end of said barrel, the skirt directed into said explosive chamber to minimize radial flow of explosive gases between the barrel and shoulder; and a second skrted disk at the outer end of said barrel to seal against entra.nce of deleterious fluid into the bore of said barrel.

GEORGE F. TURECHEK. 

